Researcher Antonio Convit, MD, says the bottom line is, "We are seeing brain changes in kids with metabolic syndrome and we don't know if this is reversible."

Children with metabolic syndrome scored 10% lower on mental tasks that are important for learning, he says. The findings appear in Pediatrics.

What to Do?

In the new study, obese or overweight teens with metabolic syndrome could not read as well, scored worse on math tests, and took longer to complete tasks than children who did not have metabolic syndrome. What's more, their brains also had physical differences.

The new study included 49 teens with metabolic syndrome and 62 without it. The more metabolic syndrome risks that participants had, the more pronounced the brain changes were, the study shows.

Convit calls for testing for insulin resistance among at-risk children, particularly those who are very overweight and those who have a family history of diabetes or heart disease.

Other solutions include having physical education programs in school. "We should invest more in physical education so kids are fitter and less likely to have insulin resistance, which is the main driver of these brain changes."

Insulin Resistance Affects Brain

Insulin is a hormone that helps the body turn sugar into energy. Insulin resistance occurs when the body does not use insulin properly.

Michele Mietus-Snyder, MD, says the new findings should serve as a wake-up call.

"Every cell in every organ system requires energy to live and insulin is the gatekeeper," she says. "Insulin resistance has reached beyond the traditional organ systems to the brain."

"We need to be very vigilant when children start to gain belly fat because we don't want children to fall behind the metabolic eight ball." If that occurs, it becomes a catch-22. "How can you expect someone to make healthy choices when they are [mentally] impaired?"

Scott Kahan, MD, MPH, is the director of the National Center for Weight and Wellness in Washington, D.C. "Metabolic syndrome was unheard of in kids until recently," he says. "It is striking that a significant number of kids have metabolic syndrome, but the fact that we can show further consequences in the brain is even more striking."